Iran's powerful military had helped Hamas, the group which controls the Gaza Strip, to plot a multi-prong attack on Israel, the most deadly in several years, a Wall Street Journal report said.

Iran helped to plan Palestinian terror group Hamas's unprecedented attack on Israel and gave approval for the assault at a meeting in Lebanon's capital Beirut last week, senior members of Hamas and Hezbollah, another Iran-backed group, told the Wall Street Journal.

Officers of Iran's Islamic Revolutionary Guard Corps (IRGC), the country's most powerful military, had been working with Hamas since August to devise their multi-prong attack on Israel by land, air and sea, they said.

Israel's attack was discussed during several meetings in Beirut that were attended by IRGC officers and representatives of four Iran-backed terror groups, including Hamas and Hezbollah. Hamas control the Gaza Strip while Hezbollah is a Shiite terror group and political faction in Lebanon, the Wall Street Journal reported.

Iranian Foreign Minister Hossein Amir-Abdollahian had attended at least two of the meetings since August, according to Hamas and Hezbollah members.

The attack on Israel was intended while the country appeared distracted by political bickering over Prime Minister Benjamin Netanyahu’s government. The strike was also aimed at disrupting US-brokered talks to normalise Saudi Arabia-Israel relations, which Iran saw as threatening, they told the publication.

The powerful Iranian military's broader plan was to create a multi-front threat "strangling" Israel from all sides -- Hezbollah and the Popular Front for the Liberation of Palestine in the north and Palestinian Islamic Jihad and Hamas in Gaza and the West Bank, said senior Hamas and Hezbollah members and an Iranian official.

Notably, Iran is setting aside other regional conflicts, including its open feud with Saudi Arabia in Yemen and focusing on IRGC's foreign resources toward financing and arming terror groups, including Hamas and Hezbollah, to attack Israel.

However, when Mahmoud Mirdawi, a senior Hamas official, was asked about the meetings with Iran in Beirut, he claimed it was a "Palestinian and Hamas decision".

A spokesperson for Iran’s mission to the United Nations said his country backed the actions by Hamas in Gaza, but asserted that Tehran did not direct them, the Wall Street Journal reported.

"The decisions made by the Palestinian resistance are fiercely autonomous and unwaveringly aligned with the legitimate interests of the Palestinian people," the spokesperson was quoted by Wall Street Journal as saying, on the condition of anonymity. "We are not involved in Palestine’s response, as it is taken solely by Palestine itself," he claimed.

US Secretary of State Antony Blinken said there was no evidence Iran was behind the latest attacks on Israel but he said there are long-standing ties between Tehran and Hamas.

Israel on Saturday launched a counteroffensive to wipe out Hamas's hideouts in the Gaza Strip, after the group launched 5,000 rockets into Israel and its members infiltrated the country by land, air and sea.